應用於多天線雲無線接取網路的動態用戶排程機制

Abstract

在本篇論文當中，我們考慮在基於最大化所有所選用戶中的最小 速率於每個時隙的動態用戶排程於一個由多個單天線RRH 和多個單 天線用戶所組成的雲無線接取式網路的框架中，使得排程結束時間盡 可能短。不做波束形成，所述的框架成為一個點對點的無線網絡，那 麼對於一個用戶來說，來自於其它非其服務基地台的干擾都是雜訊。 所以在每一個時隙, 我們必須決定適當的RRH 與用戶的配對關係讓 最大最小訊號對於干擾加雜訊比盡可能的高。我們提出了兩個啟發式 的方式在每個時隙排程用戶。做波束形成，儘管所有的用戶可以在一 個時隙中可以被同時服務，但是信道條件差的用戶不僅拖累該時隙中 的其它用戶於並且對於縮短排程可能也是一種負擔。因此，我們以某 種方式選擇當時隙中該被放棄的用戶來提升總吞吐量。而經過模擬, 我們發現在多數情況下這麼做可以帶來的更短的排程時間。

In this thesis, we consider the dynamic user scheduling in each time slot based on maximizing the minimum rate among all the selected users such that the scheduling time is as short as possible in a Cloud-RAN with multiple single antenna RRHs and multiple single antenna MUs framework. Without doing beamforming, the framework becomes a point-to-point wireless network, where a MU treats the interference from other RRHs, not its serving RRH, as noise. Then we need to choose MUs and decide the pairing relationship between RRHs and UE appropriately such that the max-min SINR is as high as possible. And we propose two heuristic ways to schedule. With doing beamforming, although all the MUs can be served simultaneous in a time slot, some MUs with bad channel conditions may suppress the total throughput and may be a burden to shorter scheduling time. Hence, we somehow abandon the burden in a time slot for better total throughput. It brings to the shorter scheduling time at most of time.